IT is a family mystery which has troubled and intrigued Kristina Derrick for 30 years and now she is asking mydailynews.com.au readers to help her solve it.

Some of the details are sketchy, but here is what she knows.

Sometime between 1983 and 1986 her grandfather, grandmother and her brother were travelling in a car from Cabarita Beach to an unknown golf club. When they turned onto the "old freeway" they witnessed a motorbike trying to overtake a car.

The bike hit the car, slid under it and then burst into flames.

The rider was trapped and as the flames began to engulf the car Ms Derrick's grandfather dragged the rider to the side of the road.

He then went back to the car, which had also caught on fire, and removed a woman and a child.

Ms Derrick's brother, aged somewhere between 13 and 16 at the time, took a series of photos.

When the police arrived Ms Derrick's grandfather left the scene.

"He was a very private man and wanted nothing more to do with the situation," she said.

Ms Derrick said she can't be sure of the exact location of the crash, but they had turned south onto a main road which ran through a winding range.

She said she had been told there had been many accidents on this stretch of road.

Ms Derrick said it was a family story which has always intrigued her and she wanted to know if the three people in the crash were safe.

Can you help solve this mystery? Comment below, send an email or telephone (07)55236214